The present study was performed to determine the factor, either duration or the temperature of heat treatment, exerting maximal and significant influence on the composition and allergenicity of egg white (EW) proteins.
Raw EW and 4 kinds of heated EW (fried EW, boiled EW for 10 minutes, boiled EW for 30 minutes, and baked EW for 20 minutes at 170℃) were prepared, and subsequently protein extraction was carried out. The proteins were separated by SDS-PAGE, and then immunoglobulin E (IgE) immunoblots were performed with the sera of 7 egg-allergic patients. Furthermore, the antigenic activities of ovalbumin (OVA), ovomucoid (OM), and ovotransferrin (OT) in different EW samples were measured by inhibition enzyme-linked Immuno-sorbent assay (ELISA).
In SDS-PAGE analysis, the intensity of the protein band at 45 kD (corresponding to OVA) decreased significantly in boiled EW (30 minutes) and baked EW, but no change was observed in the case of boiled EW for 10 minutes. In IgE immunoblots, the IgE response to 34-50 kD (OM and OVA) in boiled EW for 30 minutes decreased significantly, when compared with raw EW and other heated EWs. In inhibition ELISA, a significant decrease in the OVA antigenic activity was observed in boiled EW for 30 minutes amongst other heated EW samples. However, OM antigenic activity in all kinds of heated EW including boiled EW for 30 minutes did not reduce after heat treatment. The OT antigenic activity nearly disappeared in heated EWs except in the case of boiled EW for 10 minutes.
Amongst 4 kinds of heated EWs, the boiled EW for 30 minutes showed the most significant changes both in composition and reduction in allergenicity. Our results revealed that the duration of heat treatment had more influence on the composition and allergenicity of EW proteins than the temperature.
Egg allergy; egg white; heat treatment; ovomucoid
Buckwheat is known as a health food but is one of the major food allergens triggering potentially fatal anaphylaxis in Asia, especially in Japan and Korea. This study was conducted to investigate the characteristic of enzymatic resistance of buckwheat protein and allergenic potential. Enzymatic resistance of buckwheat protein was performed with in vitro digestibility test in simulated gastric fluid (SGF), pH 1.2, using pepsin and simulated intestinal fluid (SIF) using chymotrypsin. Reactivity of buckwheat proteins to human IgE was performed using six allergic patients sensitized to buckwheat. Buckwheat's IgE levels were measured using the Phadia UniCAP-system. Buckwheat protein, 16 kDa, still remained after 30 min treatment of pepsin on SDS-PAGE. Even though 16 kDa almost disappeared after 60 min treatment, two out of the six buckwheat patients' sera showed reactivity to hydrolysate after 60 min treatment, indicating that allergenicity still remained. In simulated intestinal fluid (SIF) using chymotrypsin, buckwheat protein, 24 kDa, showed resistance to hydrolysis with chymotrypsin on SDS-PAGE, and still had allergenicity based on the result of ELISA. Our results suggest that buckwheat proteins have strong resistance to enzyme degradation. This may be attributed in part to the allergenic potential of buckwheat. Further study should be continued regarding buckwheat allergy.
Buckwheat; hydrolysis; pepsin; chymotrypsin; allergenicity
It is known that ovomucoid, an egg allergen, is heat resistant and remains soluble after heating. However, a recent study showed that the antigenic activity of ovomucoid could be reduced by heating when egg white (EW) was mixed with wheat flour. This study was performed to determine the influence of wheat flour on the antigenic activities of EW proteins when EW is heated, and the influence of the duration of heat treatment.
A mixture of EW and wheat flour was kneaded for 10 minutes and then baked at 180℃ for 10 minutes and 30 minutes. The EW without wheat flour was also heated at 180℃ for 10 minutes and 30 minutes. The proteins were separated by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), and IgE immunoblotting was performed with the pooled sera of 5 egg-allergic patients. The antigenic activities of ovomucoid in different EW samples were measured by inhibition enzyme-linked immunosorbent assay (ELISA).
1) SDS-PAGE: the intensity of the 37-50 kD bands (overlapped bands of ovomucoid and ovalbumin) decreased significantly in the mixture of EW and wheat flour baked for 30 minutes, compared with the mixture baked for 10 minutes, heated EW and raw EW. 2) IgE immunoblot: in the mixture of EW and wheat, a remarkable decrease of IgE reactivity to 37-50 kD was observed when baked for 30 minutes. 3) Inhibition ELISA: the antigenic activity of ovomucoid decreased significantly in the mixture of EW and wheat baked for 30 minutes, but not in the heated pure EW.
This study showed that the antigenic activity of ovomucoid can be reduced by baking EW with wheat flour. The decrease in ovomucoid antigenicity in the baked mixture of EW and wheat flour was dependent on the time of heat treatment, indicating that heating should be prolonged to achieve a reduction in ovomucoid antigenic activity.
Egg white; wheat flour; hot temperature; ovomucoid
We attempted to investigate the correlation between the severity of atopic dermatitis (AD) in children and the indoor level of house dust mite (HDM) allergens. Ninety-five patients (31.1 ± 19.5 months of age) with AD were enrolled in this study, and serum specific IgE against Dermatophagoides pteronyssinus and D. farinae was measured. The severity of AD was assessed using the visual analogue scale on the same day of house dust collection. Living rooms and mattresses where the child usually slept were vacuumed for 2 minutes and concentrations of Der f 1 were measured by enzyme-linked immunosorbent assay. The skin symptoms were more severe in patients with Der f 1 concentrations in living room > 2 µg/g dust than ≤ 2 µg/g dust (P = 0.018). This difference was noted in AD patients without sensitization to HDM (P = 0.004), but not in patients with sensitization. There was no difference in symptom severity according to Der f 1 concentrations in mattresses (P = 0.062). The severity of skin symptoms is associated with indoor concentrations of HDM in children with AD, and it is likely to act as nonspecific irritants as well as allergens in AD skin lesions.
Atopic Dermatitis; Allergens; House Dust Mite
This study was performed to investigate the status of food restriction and the list of restricted foods in children with moderate to severe atopic dermatitis (AD), and to find out the effect of food restriction on the changes in nutrient intake and the severity of the disease. Sixty two patient children aged 12 months to 13 years presenting AD with a SCORing of Atopic Dermatitis (SCORAD) index between 20 and 50 were enrolled. The presence of food limitation, and list of restricted foods were surveyed through the caretakers and the patients were divided into 3 groups by the number of restricted food: non-restricted group, one to three restricted group, and more than three restricted group. Dietary intake was assessed for 3 months using a food frequency questionnaire (FFQ). Half of the subjects restricted foods. The restriction was higher in the order of soda, food additives, walnut, peanut, and other nuts as a single food item; and shellfish and crustacean group, processed foods, nuts, milk & dairy products, and meats as a food group. More than three restricted group ingested more fruits and less fish and meats, resulting in high consumption of vitamin C (p = 0.027). No significant difference in the ratio of nutrient intake by the number of restricted foods was observed in other nutrients. Significant improvement of AD symptom was observed in non-restricted group (p = 0.036) and one to three restricted group (p = 0.003). It is necessary to provide proper nutrition information and systematic and continuous nutrition management for balanced nutrient intake and disease improvement in children with AD.
Nutrient intake; Food restriction; Atopic dermatitis; Children
There are little objective data regarding the optimal practice methods of bathing, although bathing and the use of moisturizers are the most important facets to atopic dermatitis (AD) management.
We performed this study to evaluate the effect of bathing on AD.
Ninety-six children with AD were enrolled during the summer season. Parents were educated to bathe them once daily with mildly acidic cleansers, and to apply emollients for 14 days. Parents recorded the frequency of bathing and skin symptoms in a diary. Scoring AD (SCORAD) scores were measured at the initial and follow-up visits. Patients were divided into two groups, based on the compliance of bathing; poor compliance was defined as ≥ 2 bathless days.
There was an improvement of SCORAD score, itching, and insomnia in the good compliance group (all p < 0.001). The mean change in SCORAD score from the baseline at the follow-up visit was greater in the good compliance group than the poor compliance group (p = 0.038).
Daily bathing using weakly acidic syndets can reduce skin symptoms of pediatric AD during the summer season.
Atopic dermatitis; Child; Education; Skin care
The aim of this study was to analyze the natural history of atopic dermatitis (AD) and the risk factors associated with the remission of AD in Korean children. We enrolled 597 children with AD that occurred in the first year of life. A variety of factors influencing the prognosis were assessed by medical records and telephone interviews. Their outcome was classified into complete remission, intermittent, and persistent AD. AD had completely disappeared in 422 cases (70.6%), while 149 (25%) and 26 cases (4.4%) showed intermittent and persistent skin symptoms, respectively. The average healing time was 29.6 months in complete remission group and expected healing time of the AD was 60 months. None of risk factors were significant by multivariate analysis. But, in moderate-to-severe AD group, maternal diet restriction during lactation (P = 0.046) and no sensitization to cow's milk (P = 0.017) were significantly associated with remission of AD in the multivariate analysis. In conclusion, AD occurring in the first year of life disappears in a significant proportion of patients. In addition, in Korean children with moderate-to-severe AD, maternal diet restriction of allergenic food during lactation and sensitization to cow's milk seem to predict the prognosis of AD.
Dermatitis, Atopic; Natural History; Risk Factors
Adequate amounts of nutrients during pregnancy are essential for maternal, fetal and child health. This study was conducted to investigate the intakes of iron and folate and the effect of supplements on anemia status during pregnancy. One hundred sixty five pregnant women completed questionnaires which included food frequencies and supplement use, and blood tests for hematologic indices. Pregnant women were divided into four groups based on the type of supplements; single nutrient group (S), multivitamins & minerals group (M), Single nutrient + multivitamins & minerals group (S+M), and no supplement group (N). Mean iron intake was 11.1 mg from food (46.3% of Recommended Nutrient Intakes, RNIs) and 66.8 mg from supplements. Mean folate intake was 231.2 µg from food (38.5% of RNI) and 822.7 µg from supplements. In the N group, the subjects who consumed iron and folate less than EAR were 85.7% and 95.2%, respectively. The subjects consumed iron more than UL were 81.0% in the S group, 88.9% in the M group, and 97.4% in the S+M group, and the subjects consumed folate more than UL were 4.8% in the S group, 1.6% in the M group, and 25.6% in the S+M group. The mean values of hemoglobin and hemotocrit in the M group were significantly higher than those in the N group. Despite the relatively high socio-economic status of the participants, overall intakes of iron and folate from food were far below the RNIs, suggesting that a supplement is needed for adequate nutritional status during pregnancy. A multivitamin supplement seems to be more effective than a single nutrient supplement such as iron or folic acid in the prevention of anemia. Further research is required to define the appropriate amount of supplemental iron and folic acid for Korean pregnant women.
Iron; Folate; Dietary supplements; Anemia; Pregnant women
We attempted to investigate the prevalence of atopic dermatitis (AD) in Korea by using national statistics. Data on AD patients who received medical service at least once a year from 2003 through 2008 were collected from health insurance research team of National Health Insurance Corporation. Data of estimated populations during the same period were obtained from the Statistics Korea. In 2008, the prevalence of AD was 26.5% in aged 12-23 months and decreased substantially to 7.6% at age 6 yr, 3.4% at age 12 yr and to 2.4% at age 18 yr. In males, the prevalence was higher than females until 2 yr of age, while the opposite was shown in children aged 2 yr or older. In children aged less than 24 months, the prevalence of AD has increased from 19.8% to 23.8% between the years 2003 and 2008, while the prevalence showed no increase in the older age group. In conclusion, the prevalence of AD in 2008 peaked during infancy up to 26.5% and decreased thereafter. Our findings also suggest that increasing prevalence of AD in children less than 24 months might be responsible for the recent increase in the prevalence of AD in Korean children.
Prevalence; Dermatitis, Atopic; Korea
Regional dietary habits and cooking methods affect the prevalence of specific food allergies; therefore, we determined the effects of various pH conditions on major peanut allergens. Peanut kernels were soaked overnight in commercial vinegar (pH 2.3) or acetic acid solutions at pH 1.0, 3.0, or 5.0. Protein extracts from the sera of seven patients with peanut-specific IgE levels >15 kUA/L were analyzed by SDS-PAGE and immunolabeling. A densitometer was used to quantify and compare the allergenicity of each protein. The density of Ara h 1 was reduced by treatment with pH 1.0, 3.0, or 5.0 acetic acid, or commercial vinegar. Ara h 2 remained largely unchanged after treatment with pH 5.0 acetic acid, and was decreased following treatment with pH 1.0, 2.3, or 3.0 acetic acid. Ara h 3 and Ara h 6 appeared as a thick band after treatment with pH 1.0 acetic acid and commercial vinegar. IgE-binding intensities to Ara h 1, Ara h 2, and Ara h 3 were significantly reduced after treatment with pH 1.0 acetic acid or commercial vinegar. These data suggest that treatment with acetic acid at various pH values affects peanut allergenicity and may explain the low prevalence of peanut allergy in Korea.
Acetic acid; allergens; Ara h 1 allergen; Ara h 2 allergen; Ara h 3 allergen; peanuts
Food allergy is an important public health problem affecting 5% of infants and children in Korea. Food allergy is defined as an immune response triggered by food proteins. Food allergy is highly associated with atopic dermatitis and is one of the most common triggers of potentially fatal anaphylaxis in the community. Sensitization to food allergens can occur in the gastrointestinal tract (class 1 food allergy) or as a consequence of cross reactivity to structurally homologous inhalant allergens (class 2 food allergy). Allergenicity of food is largely determined by structural aspects, including cross-reactivity and reduced or enhanced allergenicity with cooking that convey allergenic characteristics to food. Management of food allergy currently focuses on dietary avoidance of the offending foods, prompt recognition and treatment of allergic reactions, and nutritional support. This review includes definitions and examines the prevalence and management of food allergies and the characteristics of food allergens.
Food allergy; Allergens; Cross reactions; Disease management
Cow's milk is one of the most common food allergens in children with atopic dermatitis (AD). This study was conducted to describe the natural course of cow's milk allergy in children with AD, and to identify factors predictive of outcome. To accomplish this, we reviewed the medical records of 115 children who were diagnosed with AD and cow's milk allergy before 24 months of age to evaluate their clinical characteristics and prognostic factors. During a follow-up period of 24 to114 months, the median age for tolerance to cow's milk was found to be 67 months. Multivariate analysis using the Cox proportional hazard model revealed that the peak cow's milk-specific IgE level within 24 months after birth was the most important factor for prediction of the outcome of cow's milk allergy. In conclusion, half of the children younger than 24 months of age with AD and cow's milk allergy could tolerate cow's milk at 67 months of age. The peak cow's milk-specific IgE level within the first 24 months of birth is useful to predict the prognosis of cow's milk allergy in children with AD.
Milk; Food Hypersensitivity; Immunoglobulin E; Prognosis
This was a prospective cohort study of 976 infants from birth to 12 months of age. Infants were fed breast milk, goat infant formula, cow infant formula, or a combination of formula and breast milk during the first 4 months of age. Data on type of milk feeding and infant growth (weight and height) were collected at birth and at 4, 8, and 12 months during routine clinical assessment. The number and consistency of bowel motions per day were recorded based on observational data supplied by the mothers. Infants fed breast milk or goat or cow infant formula during the first 4 months displayed similar growth outcomes. More of the infants fed cow infant formula had fewer and more well-formed bowel motions compared with breast-fed infants. The stool characteristics of infants fed goat formula resembled those of infants fed breast milk.
Infant formula; infants; growth
Environmental pollutants are thought to be one of major triggers of atopic dermatitis (AD).
We attempted to evaluate the clinical effects of environment with low indoor pollutant levels on AD management.
Fifty-one children (mean age 1.7 years) with moderate to severe AD who failed to show improvement with conventional management were recruited. Disease severity was assessed by SCORAD (Scoring of AD) indices. They were admitted in a low pollutant oom for 3-4 days (mean 3.3 days) which was designed to keep low levels of dust, house dust mites, micro-organisms, and indoor air pollutants such as total volatile organic compounds (TVOCs), particulate matter (PM), and so on. Air pollutant levels in the low pollutant room were lower than primary standards defined by the Korean Ministry of Environment. we compared disease severity on admission and after discharge, and the pollutant levels of each patient's home and low pollutant room.
The SCORAD was significantly reduced from 42.0 ± 11 .5 to 29.8 ± 8.9 (p < 0.001) by management in a low pollutant room. PM2.5, PM10, formaldehyde, TVOCs, carbon dioxide, bacterial suspensions, and indoor molds were significantly higher in the patient's home than low pollutant room. Out of 29 patients who deteriorated after discharge to their home, 8 patients were admitted again, and their SCORAD was rapidly decreased from 53.1 ± 16.2 to 39.2 ± 9.8 (p = 0.036).
Indoor air pollutants are likely to affect AD in susceptible individuals. Environmental control to lower indoor air pollutant levels might be necessary for better management of AD in some patients.
Atopic dermatitis; Childhood; Environment; Air pollution; Indoor
Atopic dermatitis (AD) is the most common chronic inflammatory skin disorder in children, with a worldwide cumulative prevalence in children of 8-20%. The number of AD patients is beyond the level that can be dealt with at clinics and it is time to make an effort to reduce the number of AD patients in the community. Thus, caregivers and all persons involved with AD management, including health care providers, educators, technologists and medical policy makers, should understand the development and the management of AD. Although a number of guidelines such as Practical Allergy (PRACTALL) report have been developed and used, community understanding of these is low. This is probably because there are still remarkable differences in management practices between specialists and between countries and most of the reported guidelines have been prepared for physicians. From the viewpoint of providing a basis for a multidisciplinary team approach, easily comprehensible guidelines for organizing treatment of AD, i.e. an Atopic Dermatitis Organizer (ADO), are required. guidelines should be simple and well organized. We suggest an easy approach with a new classification of AD symptoms into early and/or progressive lesions in acute and/or chronic symptoms. The contents of this ADO guideline basically consist of 3 steps approaches: conservative management, topical anti-inflammatory therapy, and systemic anti-inflammatory therapy.
Atopic dermatitis; classification, Management; Guideline
Infants with chronic respiratory symptoms should be evaluated thoroughly because there are various causes which are different from those of children and adolescents.
This study was designed to investigate the relationship between chronic respiratory symptoms and bedtime bottle feeding in infants after the age of 6 months.
We conducted a prospective study that included 44 infants who presented with respiratory symptoms for more than 8 weeks and also had been bottle-fed during bedtime even after 6 months of age. The infants were divided into 2 groups; infants who discontinued bedtime bottle feeding and those who did not. Respiratory symptom scores were graded with a four-point scale at 0, 1, 2 and 3 months, and were compared between the 2 groups.
Twenty eight infants (63.6%) stopped being bottle-fed during bedtime and 16 infants (36.4%) were still bottle-fed. The respiratory symptom scores were significantly decreased in infants who stopped bedtime bottle feeding (p = 0.0003).
It is suggested that prolonged bedtime bottle feeding might be one of the causes of chronic respiratory symptoms in infants.
Feeding methods; Bottle feeding; Infants
The peptide microarray is a novel assay which facilitates high-throughput screening of peptides with a small quantity of sample.
We sought to use overlapping peptides of milk allergenic proteins as a model system to establish a reliable and sensitive peptide microarray-based immunoassay for large scale epitope mapping of food allergens.
A milk peptide microarray was developed using commercially synthesized peptides (20-mers, 3 offset) covering the primary sequences of αs1-, αs2-, β-, and κ-caseins, and β-lactoglobulin. Conditions for printing and immunolabeling were optimized using a serum pool of five milk-allergic patients. Reproducibility of the milk peptide microarray was evaluated using replicate arrays immunolabeled with the serum pool, whereas specificity and sensitivity were assessed using serial dilution of the serum pool and a peptide inhibition assay.
Our results show that epitopes identified by the peptide microarray were mostly consistent with those identified previously by SPOT membrane technology, but with specific binding to a few newly identified epitopes of milk allergens. Data from replicate arrays were reproducible (R≥0.92) regardless of printing lots, immunolabeling and serum pool batches. Using the serially diluted serum pool, we confirmed that IgE antibody binding detected in the array was specific. Peptide inhibition of IgE binding to the same peptide and overlapping peptides further confirmed the specificity of the array.
A reliable peptide microarray was established for large scale IgE epitope mapping of milk allergens and this robust technology could be applied for epitope mapping of other food allergens.
Epitope mapping; peptide microarray; allergy; milk allergen